1. Field Of The Invention
The invention relates to an electronic operational control device for a piloting member, called the controlled piloting member, of an aircraft comprising a piloting device equipped, for each flying member of the aircraft, with two such piloting members connected (by a completely mechanical kinematic chain or at least partly electrically) to this flying member, so that the aircraft can be piloted simultaneously by two people: a captain and a copilot. Throughout the text, the term “piloting” and its derivatives denote, unless otherwise stated, the flying of an aircraft by at least one human pilot operating at least one piloting member such as a stick, handle, rudder bar, pedal, etc., connected to at least one flying member such as a control surface or a throttle control of the aircraft, etc. The term “command” and its derivatives denote in the traditional manner in aeronautics the fact of supplying a device with signals which bring about a predetermined action of said device. The term “monitor” and its derivatives denote in the traditional manner in aeronautics the fact of processing measurements carried out on a device and comparing them with predetermined values to detect the occurrence of operating faults (i.e. faults arising from any failure in a system (device and/or software), as opposed in particular to use faults arising not from a failure, but from errors of a user (pilot or copilot) or from the aircraft departing from its flight envelope). An operational control device for a piloting member is a device having at least one monitoring function for this piloting member, and also being able to perform other functions, in particular for commanding this piloting member.
2. Description Of The Related Art
A piloting device comprising servo coupling (logically and electronically) of a pilot's stick and a copilot's stick has already been proposed. Motors enable simulation of the feel of traditional mechanical sticks and the tracking of each stick by the other.
US 2005/0080495 describes such a piloting device employing a centralised flight computer and making it possible to obtain coupling of the sticks of a pilot and a copilot. This device also makes it possible to supply a summed signal of the commands of the two pilots. Such a device makes it possible to detect piloting faults, i.e. commands given by the copilot conflicting with those given by the pilot (or a command of the pilot conflicting with that of the automatic pilot) and to deactivate the coupling between the two sticks. This device does not perform a monitoring function.
In addition, such a device poses the problem of its reliability and of monitoring the occurrence of possible operating faults (failures) to ensure good operating safety.
EP 0 759 585 poses this problem and points out that such aeronautical systems must be fault tolerant and in particular integrate redundant devices. The solution recommended by this document consists in providing, for each piloting stick, on the one hand complete redundancy of the motors, detection sensors and circuits for generating force feedback sensations, and on the other hand connected command and monitoring computers for “self-monitoring” the command signal of the motor associated with this stick, comparing it with a motor current signal, and comparing measured voltage signals with a reference signal, the monitoring computer monitoring the command computer, the two computers being capable of deactivating the motor. Such a solution, which is traditional in its principle, is heavy, complex and costly in its implementation and its operation. In particular, it requires a specific monitoring computer for each stick. In addition, it remains imperfect insofar as certain failures which are liable to occur on such a monitoring computer will not necessarily be detected themselves.